Characteristics and kinetic analysis of pyrolysis of forestry waste promoted by microwave-metal interaction

In the present work, a method of pyrolyzing forestry waste (FW) under microwave-metal interaction was proposed. The kinetic analysis of the process was carried out using a microwave thermogravimetric analyzer. The mechanism of FW pyrolysis under microwave-metal interaction was discussed from the perspective of microwave-induced metal discharge and non-discharge processes. The initial pyrolysis temperature T-i reduced, and the maximum pyrolysis rate R-m and pyrolysis characteristic index S increased by employing a method where microwave and metal were coupled. The number of metals inserted also significantly affected the pyrolysis behavior. R-m in the presence of one metal was 92.3% higher than that recorded in the absence of metal. The results of kinetic analysis revealed in the presence of metal, the activation energies at 400 W and 560 W were 51.7% and 57.5% lower, respectively, than the activation energy recorded in the absence of metal. Multiple effects of light, heat, and plasma produced by microwave-induced discharge caused the local pyrolysis of FW. The promotion of FW pyrolysis in the non-discharge stage was primarily caused by the microwave absorption of carbon into heat and the conversion of current on the metal surface into Joule heat. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study proposed a method of pyrolyzing forestry waste under microwave-metal interaction and found that coupling microwave and metal can enhance pyrolysis efficiency, with the number of metals inserted significantly affecting the pyrolysis behavior.